Digital flood-inundation maps for a 6.2 mile reach of the Tippecanoe River at Winamac, Indiana (Ind.), were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage 03331753, Tippecanoe River at Winamac, Ind. Current conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the Internet from the USGS National Water Information System at http://waterdata.usgs.gov/in/nwis/uv?site_no=03331753. In addition, information has been provided by the USGS to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps/). The NWS AHPS forecasts flood hydrographs at many sites that are often collocated with USGS streamgages, including the Tippecanoe River at Winamac, Ind. NWS AHPS forecast peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation and forecasts of flood hydrographs at this site.

For this study, flood profiles were computed for the Tippecanoe River reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relations at the Tippecanoe River streamgage, in combination with the current (2014) Federal Emergency Management Agency flood-insurance study for Pulaski County. The calibrated hydraulic model was then used to determine nine water-surface profiles for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the highest stage of the current stage-discharge rating curve. The 1-percent annual exceedance probability (AEP) flood stage (flood with recurrence intervals within 100 years) has not been determined yet for this streamgage location. The rating has not been developed for the 1-percent AEP because the streamgage dates to only 2001. The simulated water-surface profiles were then used with a geographic information system (GIS) digital elevation model (DEM, derived from Light Detection and Ranging [lidar]) in order to delineate the area flooded at each water level. The availability of these maps, along with Internet information regarding current stage from the USGS streamgage 03331753, Tippecanoe River at Winamac, Ind., and forecast stream stages from the NWS AHPS, provides emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.